Abstract: To address issues of journal bearing damage and uneven flow distribution in the dual-ring seal pads of an operational nuclear generator, this study employs a multi-field coupled spatial equilibrium algorithm to analyze their lubrication and load-bearing characteristics, aiming to resolve problems of wear, deformation, and failure. By integrating flow fields, temperature fields, and thermoelastic deformation, a multi-field coupled model is established to reveal the effects of oil film pressure, contact pressure, temperature distribution, and deformation on the performance of the seal pads. The study identifies stress concentration regions and operational clearance variations as the primary causes of seal pad damage. To enhance sealing performance, an optimized design is proposed by increasing the oil-sealing edge width on the air side and reducing it on the hydrogen side. After optimization, the relative load-bearing capacity of the seal pads increased by more than twofold, while the thrust-to-weight ratio decreased by 50%, achieving stable floating under various operating conditions and demonstrating excellent load-bearing capacity and compliance. The results indicate that the optimized design significantly improves the lubrication performance and operational reliability of the seal pads, providing valuable theoretical insights and practical guidance for the design and optimization of dual-ring oil sealing systems.

Key words: dual-flow oil seal pad, sealing edge parameters, thrust pad weight ratio, contact load, responsiveness